The present invention relates to an apparatus for forming an ultrathin film called a Langmuir-Blodgett Film (LB film).
Recently a method of constructing, an organic ultrathin film, known as an LB film, has quickly become popular as a thin film formation technique. The LB film has various advantages, such as good molecular controllability, provision of and therefor it can be adapted to a wide variety of; usages and is easily prepared under normal temperature and pressure. The application thereof has been therefore researched in various fields.
A conventional apparatus or system for forming or preparing the LB film consists of, for example, a packing unit, for compressing a sample developed on the surface of subphase solution stored in a first tank by moving a barrier along the upper surface of the subphase solution, called merely "subphase" hereinafter, and a sampling unit for sampling a monomolecular film of the sample, which is oriented and packed by the packing unit, on a surface of a film carrier plate as a substrate. The packing unit is provided with a second tank for regulating the temperature of the subphase, a sensor for detecting the temperature of the solution in the second tank and a temperature controller for regulating the temperature of the solution in the second tank in response to a signal transmitted from the sensor. Accordingly, the packing unit performs only the temperature control of the subphase.
In such a conventional apparatus, however, attention has not been paid to the temperature of the ambient atmosphere, surrounding the apparatus, thus providing the following problems.
Namely, when the temperature of the subphase increases over the ambient temperature, steam is generated in an extreme case, and steam is condensed on the surface of the substrate preliminarily disposed above the subphase for sampling the monomolecular film. This results in poor sampling of the monomolecular film because of dew condensation formed on the substrate. On the other hand, when the temperature of the subphase becomes well below ambient temperature of the ambient atmosphere, dew condensation is formed on the peripheral surface of the first tank in which the subphase is stored, resulting in that the barrier cannot sufficiently compress, i.e. pack, the sample of the subphase. This causes insufficient control of the film pressure.